<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>

	<% 
		//若可以获取到请求参数 name, 则打印出欢迎信息。把登录信息存储到 Cookie 中，并设置 Cookie 的最大时效为 30S
		String name = request.getParameter("name");
		if(name != null && !name.trim().equals("")){
			Cookie cookie = new Cookie("name", name);
			cookie.setMaxAge(30);
			response.addCookie(cookie);
		}else{
			//从 Cookie 中读取用户信息，若存在则打印欢迎信息
			Cookie [] cookies = request.getCookies();
			if(cookies != null && cookies.length > 0){
				for(Cookie cookie : cookies){
					String cookieName = cookie.getName();
					if("name".equals(cookieName)){
						String val = cookie.getValue();
						name = val;
					}
				}
			}			
		}
		
		if(name != null && !name.trim().equals("")){
			out.print("Hello: " + name);
		}else{
			//若既没有请求参数，也没有 Cookie，则重定向到 login.jsp
			response.sendRedirect("login.jsp");
		}
		
		

	%>

</body>
</html>